Coffee Blending

The inertia our greens club has introduced means we had better start to get good at blending. I generally drink SO enjoying the individual flavours, however I want to know all about blending with the same curiosity and thoroughness as all the other coffe aspects we learn and master. It's a personal focus in the months ahead.

This may mean some pairing up with another greens club member so that we can stick to 2 or 3 beans each (Dave is close by thankfully ) for practicality.

Where does one start?

Well, knowing each bean individually obviously, fumbling through different ideas about what our palate likes (or is ready to like, a soapbox area for me) or is it? Time to learn what those walking the path before us have to pass on. I thought I would start this thread with any useful links I find. I haven't read these yet but here's my start list for study:

Actually, I was expecting to find a lot more but it's a starter for 10. One of my favourite writers (Kenneth David) has this to add:

Blending for Espresso - Introduction:
Blends can combine coffees brought to different degrees of roast, coffees with different caffeine contents, and/or straight coffees from different origins. The overriding goal of specialty blenders is simply producing a coffee that is more complete and pleasing in its totality than any of its unblended components would be alone. This goal is particularly important in espresso, because the concentrated cup produced by the espresso brewing method tends to reward balance and completeness rather than the often interesting but imbalanced flavour profiles of coffees from single origins.

Blending Philosophies:
Complete and Pleasing. In the case of an espresso blend, what constitutes "more complete and pleasing" is obviously relative: relative to the palate of the blender, to the expectations of the consumer, and to the traditions to which both blender and consumer refer.

Tasting terms:
At this point it might be useful to refer to the array of tasting terms listed earlier: acidity, body, aroma, finish, sweetness, bitterness, and so on. It would be safe to say that all espresso blends everywhere aspire to as full a body as possible, as much sweet sensation as possible, and as much aroma and as long and resonant a finish as possible. The differences arise with acidity and with the bitter side of the bittersweet taste equation. Most northern Italian roasters present blends with almost no acidy notes whatsoever, whereas North American espresso blends often maintain some of the dry, acidy undertones most Americans and Canadians are accustomed to in their lighter-roasted coffees. This difference is simply a matter of choice and tradition. North Americans are used to acidy, high-grown Latin America coffees, and Italians are accustomed to drinking either Africa Robusta or lower-altitude Brazil Arabica.

Kenneth's own thoughts:
My own position, for what it's worth, is that acidy notes need to be felt but not tasted in espresso blends. They should be barely discernible, yet vibrating in the heart of the blend. Recall that acidity, or dryness, is a property of the bean that diminishes as the roast becomes darker, to eventually be replaced entirely by the bittersweet, pungent flavour notes characteristic of dark roasts. The value of the bitter side of the bittersweet equation is also an issue in blending philosophy, with Italian and Italian-style roasters coming down more on the sweet side, and North American roasters more on the bittersweet. As I pointed out in discussing style of roast, this difference is reflected in the somewhat lighter roasts preferred by Italian roasters, opposed to the darker styles favoured by most North American roasters.

So, on both accounts, blending philosophy and style of roast, northern Italians put a premium on sweetness and smoothness and North Americans on punch. It is clear why North Americans might prefer a punchier, more pungent and more acidy espresso coffee: They need the power of such flavour notes to carry through all of the milk they tend to add to their "lattes" and cappuccinos. Italians generally take their espresso undiluted and so might logically prefer a smoother, sweeter blend. But such an explanation may be entirely too rational. After all, those purist Italians also tend to dump large quantities of sugar into their smooth, sweet espresso blends. Probably taste in espresso blends is simply another irrationality of culture and tradition.

Blending Principles:
At any rate, if heavy body, seductive aroma, a muted acidity, and (in the case of American-style espresso blends) sweet-toned pungency are the goals, how does one attempt to achieve these goals in blending? In general, roasters choose one more coffees that provide a base for a blend, additional highlight coffees that contribute brightness, energy and nuance, and (often but not always) bottom-note coffees that intensify sensations of body and weight.

Base Coffees:
Coffees that provide the base for espresso blends should not be neutral, at least not in my view. They definitely should not be dull or bland. They should be agreeable, without distracting idiosyncrasy or overly aggressive acidity, round and sweet, and they should take a dark roast well. The classic base for espresso is Brazil coffees that have been dry-processed, or dried inside the fruit, a practice that promotes sweetness and body. Peru and some Mexico coffees (all of which are wet-processed) also make a gentle but lively base for espresso. Coffees from the Indonesian island of Sumatra are favourite base coffees among many West-Coast-style American blenders. Like Brazils, Sumatras are low-keyed, rather full-bodied coffees, but brought to a dark roast they tend to be bittersweet and pungent, qualities suited to the dark-roasted, sharp, milk-mastering blends favoured by caffe-latte-happy West-Coasters.

Highlight Coffees:
These may be any coffee with character, energy, and power. Kenya, with its resonant dimension and wine-like acidity, is a favourite highlight coffee among American blenders. Other blenders may prefer the round, clean power of good Costa Ricas, the twistier, often fruit-toned energy of Guatemala Antiguas, or the singing, floral sweetness of washed Ethiopias.

Bottom-Note Coffees and the Robustas Controversy:
Blenders often add coffees whose primary contribution to the cup is weight and character. Bottom-note coffees are particularly important in espresso, where resonance and body are paramount. Sumatra Mandhelings are sometimes used as bottom-note coffees, as are specially handled coffees like India Monsooned Malabar and aged coffees. The most controversial bottom-note coffees are the heavy but inert coffees of the Robusta species. Italian blenders use Robustas freely in their espresso blends to promote body and the formation of crema, the golden froth that covers the surface of a well-made Tazzina of espresso. North-American blenders use Robustas in their espresso blends very sparingly, if at all. I have waffled about the value of Robustas in espresso blends over the years, but at this moment I am a Robusta nay-sayer. To my palate Robustas are simply too dull and lifeless. They may contribute body, but in return they tend to suck life out of a blend, absorbing nuance and deadening the profile.